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Nutrigenetics and Nutrigenomics: The Interplay of Food and Genes
] Overview: The role of nutrition in human development throughout the lifespan is truly profound. From playing a crucial role in how robustly we grow during adolescence to influencing our moods, behavior and phenotype as adults, food is perhaps the most important "essential need" in our lives. Without food we cannot survive, and without good food, we cannot function optimally. And while our genetic makeup determines roughly 50% of the outcome of our health (propensity for disease, likelihood of being overweight etc.), the other 50% is a result of environmental factors, of which nutrition is paramount. Just as smoking cigarettes and over-consumption of alcohol can put us at risk for developing cancers and other life-threatening ailments, so, too, can poor eating habits and malnutrition put us at risk for both under-development and illness. While it has only been within the past 20 years that scientists, medical doctors and the general public have become increasingly aware of the effects of food on our wellbeing, this new-found importance of food in relation to disease has given rise to Nutrigenetics and Nutrigenomis--two emerging fields in genetics and genomics that study the effects of nutrition on gene expression and how a particular individual "experiences" food based upon his or her unique genome. As stated in UC Davis' "Nutritional Genomics:" ] "To prevent the development of disease, nutrition research is investigating how nutrition can optimize and maintain cellular, tissue, organ and whole body homeostasis. This requires understanding how nutrients act at the molecular level. This involves a multitude of nutrient-related interactions at the gene, protein and metabolic levels. As a result, nutrition research has shifted from epidemiology and physiology to molecular biology and genetics." Nutrigenomics and nutrigenetics was born from this new vein of thinking, where food is recognized as influencing both the expression of genes and the overall homeostasis of an individual. Nutrigenetics: Nutrigenetics is the study of how individual humans respond to food based on their genetic makeup, and how genetic susceptibility to disease can be manifested or mitigated through nutritional concessions. Because human beings vary in their DNA and SNPs, and SNPs have been known to influence how an individual metabolizes food, nutrigentics aims to create customizable nutrition protocols for every individual. Essentially, this field follows in the direction in which medicine is headed, with a focus on bioindividuality, and the notion that what works for one person in terms of diet or treatment may not work for someone else. To identify an individual's nutrigenetic profile, a cheek swab or blood analysis is carried out, with the resulting DNA being analyzed via a "candidate gene approach," where specific possible risk genes are identified from the blood profile or swab. From here, various experiments can be conducted to determine if, indeed, there is a match between the candidate gene and nutrition. For example, the LCT gene is responsible for instructing the body to make the lactase enzyme, and mutations in this gene can cause an individual to be lactose intolerant. The nutrigenetic profile would be able to identify this lactose intolerance, and subsequent dietary tests (like having the individual consume milk and assess for common intolerance symptoms) could be administered to determine whether or not the profile accurately identified a link between a person's genetics and the nutrition they should or should not be consuming. Of note, there is a company called My Diet Clinic that offers the public the opportunity to have their nutrigenetic profile created and deciphered in the same manner in which 23AndMe does, via a saliva sample. Nutrigenomics: While nutrigenetics focuses on the individual and identifying the type of diet a certain person should follow based on his or her genes, Nutrigenomics is a much broader field, employing a "systems biology" approach that hones in on the role food plays in activating genes that cause specific illnesses. Moreover, nutrigenomics is particularly focused on employing already-existing genetic technologies to study the interaction of diet and genes. Specifically, technologies that assess the transcriptome, proteome and metabolome have been used in nutrigenomic research, including DNA microarrays, exon and tiling arrays, and various forms of chromotography, spectrometry and gel electrophoresis. All of these traditional genetic tests aim to assess the effects of diet on the biochemistry of the body. Nutrigenomics sees nutrients as "signals" that have the ability to change gene expression, protein expression and metabolite production. The Future of Food and Our Genes: Given that both nutrigenetics and nutrigenomics are such new fields, there remains incredible potential for the breadth of influence they may have on the future of human health. As is apparent, there is no longer a "one-size-fits-all" diet, but rather a customizable regiment that accounts for the specific individual, right down to that person's genome. Nutrigenomics employs genetic technologies to determine how food influences genes at the cellular level, while nutrigenetics seeks to identify how our genes can be used to predict the types of foods we should or should not eat, at the individual level. Together, these two fields will likely become exceedingly popular in an age of increasing customizability, providing medical professionals with further tools for treating obesity, diabetes, food allergies and a slue of other health concerns. References: Faseb, J. "Nutrigenomics and Nutrigenetics: The Emerging Faces of Nutrition." PubMed Medline. October 2005. Harrington, LK et al. "Lactose Intolerance." Genetics Home Reference, NIH.org. 2010 Keijer, J. "Nutrigenetics of Bodyweight Regulation: A Rationale for Careful Dissection of Individual Contributors." Nutrients, 2014. The NCMHD Center of Excellence for Nutritional Genomics (2012). "Nutritional Genomics". University of California Davis. "Nutrigenetics," Wikapedia 2014 "Nutrigenomics," Wikapedia 2014.